Owing to the increasing complexity of applications in the sector of informative motor vehicle electronics, which can in the meantime be referred to as multimedial, novel concepts have become necessary for linking various devices in the network.
For example, it should at least be possible for the car radio, the mobile telephone and the navigation system to communicate with one another such that, for example, the reproduction of music by the car radio is switched to mute and the mobile wireless connection is operated via the radio loudspeaker if the user wishes to make a telephone call. However, it is clear that this is only a very simple application case and the multimedial linking of the vehicle electronics in the network is subject to barely any limitations in order to satisfy the demands of the customers.
In order to fulfill these complex requirements, in the meantime optical data transmission has become established for these connections in the automobile sector. In this regard, a novel standard entitled MOST® has been specially developed. The specifications of the MOST® standard are published, inter alia, as “MAMAC Specification” Rev 1.0, 11/2002, Version 1.0-00 at http://www.mostnet.de/downloads/Specifications/MAMACSpecification—1VO-00.pdf and at http://www.mostnet.de/downloads/Specifications/MOST %20Physical %20Layer %20Specification/010223 WgPhy Drawings.zip. Reference is made to the specifications on which the MOST® standard is based, and the contents of these specifications are made completely the subject matter of this disclosure, by reference.
A compact type of optical MOST® connector comprises electro-optical converters which are fixed to the rear side of the connector. These connectors contain, in the interior, coupling elements for the purpose of connecting the converters.
Until now, plastic fibers, for example made from polymethyl methacrylate (PMMA) or polycarbonate (PC), have often been used in conjunction with MOST® connectors. Although they have a number of advantages, the relatively low temperature resistance under some circumstances leads to difficulties. Under extreme conditions, which need to be taken into consideration, temperatures in the range up to 100° C. may occur in an automobile. In the event of such temperatures, an accelerated ageing process sets in, in particular of the polycarbonate, with the result that the properties are permanently impaired.
The use of other fibers in place of the plastic fibers is, however, usually refused, in particular since the diameter of such fibers is substantially smaller than that of the conventionally used plastic fibers. This is because, owing to this small fiber diameter, considerable difficulties result when coupling them to the existing FOTs.
In principle, special devices are known for coupling optical fibers to light element modules. For example, a coupling is described in the patent DE 100 15 867 C2 which attempts to reduce the degree to which the transmission is impaired. It is proposed to provide a coupling which has an optical waveguide, which tapers in the form of a cone and has a lens, which is formed at the end of the large diameter, and also has a circular flange-like guide. However, this coupling, as a specially manufactured individual piece, is extremely complex and therefore cost-intensive in terms of production. Furthermore, dust may collect in the region of the lens, which reduces the transmission quality. In addition, the coupling needs to be inserted with a predetermined orientation, which entails the risk of errors during assembly. Finally, the coupling is in any case not designed for the connection of a thin fiber to a relatively large light element module.
All in all, however, the known solutions are worthy of improvement. On the other hand, in this severely contested market, even what appear to be only slight qualitative and/or cost-related advantages are sufficient in order to gain a decisive advantage in the competition on the market.